Industrial wastewater treatment faces challenges in effectively and sustainably removing a variety of pollutants. This study investigates the potential of biochar derived from sewage sludge as a novel and environmentally responsible solution. Biochar was produced from sewage sludge through pyrolysis at three temperatures (300, 500, and 700 ℃). The biochar’s effectiveness in removing major industrial pollutants, including heavy metals (Pb, Cd, and Cr), organic compounds (phenol and toluene), and nutrients (nitrogen, phosphorus), was evaluated through batch adsorption trials and column examinations. Results showed that sludge biochar pyrolyzed at 500 ℃ (SB500) demonstrated the best pollutant removal performance, with maximum adsorption capacities of 156 mg/g for Pb, 98 mg/g for phenol, and 45 mg/g for phosphate. These high adsorption capacities indicate SB500’s efficiency in removing both inorganic and organic pollutants from wastewater. Regeneration studies revealed that the biochar retained over 80% of its initial adsorption capacity after five cycles, demonstrating its reusability. A cost–benefit analysis on industrial wastewater treatment indicated that sludge biochar could potentially reduce overall treatment costs by 15–20% and address sludge disposal issues. This study highlights the practical application of sludge biochar in industrial wastewater treatment, offering a sustainable approach that aligns with circular economy principles in waste management and environmental conservation.